Management Of Thoracic Aortic Aneurysms Research Articles

Arterial hypertension and aortic root dilatation: an unsolved mystery

Introduction: Acute and chronic aortic syndromes are associated with substantial morbidity and mortality. Silent risk factors such as arterial hypertension and aortic root dilatation can increase the likelihood of aortic dissection or rupture. The relationship between arterial hypertension and the dimensions of the aortic root dimension is a topic of active debate. Materials and methods: We reviewed the literature on the physiopathology, diagnosis, natural history, and management of thoracic aortic aneurysms. Results: Biological variables influencing the size of the aorta include age, sex, body surface area, pressure values, and stroke volume. Pathologic enlargement of the thoracic aorta can be caused by genetic, degenerative, inflammatory, traumatic, or toxic factors. Studies investigating the correlation between aortic dimensions and arterial pressures (diastolic, systolic, or pulse) have produced discordant results. Discussion: Classically, emphasis has been placed on the importance of hypertension-related degeneration of the medial layer of the aortic wall, which leads to dilatation of the thoracic aorta, reduced aortic wall compliance, and increased pulse pressures. However, there are no published data that demonstrate unequivocally the existence of a pathogenetic correlation between arterial hypertension and aortic root dilatation. Furthermore, there is no evidence that antihypertensive therapy is effective in the management of nonsyndromic forms of aortic root dilatation. An interesting branch of research focuses on the importance of genetic predisposition in the pathogenesis of thoracic aortic aneurysms. Different genetic backgrounds could explain differences in the behaviour of aortic walls exposed to the same hemodynamic stress. Further study is needed to evaluate these focal physiopathological aspects.

National trends and regional variation of open and endovascular repair of thoracic and thoracoabdominal aneurysms in contemporary practice

Successful surgical management of thoracic aortic aneurysms (TAA) and thoracoabdominal aortic aneurysms (TAAA) has historically relied upon open surgical repair (OSR). More recently, the advent and application of thoracic endovascular stent graft aneurysm repair (TEVAR) permutations have become increasingly performed in contemporary practice. To better determine the effect of TEVAR techniques on OSR, we examined national and regional trends in treatment use. All Medicare patients from 1998 through 2007 undergoing isolated TAA and TAAA repair were analyzed using a clinically validated algorithm using diagnostic International Classification of Disease 9th revision (ICD-9; 441.1, 441.2, 441.6, 441.7, 441.9) codes and procedural (ICD-9 OSR: 38.35, 38.45 and TEVAR: 39.73, 39.79) codes. Differential rates of OSR and TEVAR were compared across census tract regions during the study interval. Total complex aortic repairs increased by 60%, from 10.8 to 17.8/100,000, between 1998 and 2007 (P < .001). A dramatic increase occurred in TEVAR (not performed in 1998, 5.8/100,000 in 2007) during the study period, but OSR rates remained stable during the same interval (10.7 to 12.0/100,000 in 2007, P = NS). There was substantial regional variation for both OSR and TEVAR. This regional variation was greater in OSR (range, 8.8-16.7/100,000) than in TEVAR (range, 4.5-6.9/100,000). Degenerative TAA and TAAA aneurysms are being repaired in the United States at an increasing rate. This reflects the rapid acceptance of TEVAR, which apparently supplements rather than supplants OSR. There appears to be greater regional variation in OSR compared with TEVAR. These data may have significant implications for those interested in the effect of new technologies on health care and cost containment.

Ipertensione arteriosa e dilatazione dell’aorta toracica: un mistero insoluto

Acute and chronic aortic syndromes are associated with substantial morbidity and mortality. Silent risk factors such as arterial hypertension and aortic root dilatation can increase the likelihood of aortic dissection or rupture. The relationship between arterial hypertension and the dimensions of the aortic root dimension is a topic of active debate. We reviewed the literature on the physiopathology, diagnosis, natural history, and management of thoracic aortic aneurysms. Biological variables influencing the size of the aorta include age, sex, body surface area, pressure values, and stroke volume. Pathologic enlargement of the thoracic aorta can be caused by genetic, degenerative, inflammatory, traumatic, or toxic factors. Studies investigating the correlation between aortic dimensions and arterial pressures (diastolic, systolic, or pulse) have produced discordant results. Classically, emphasis has been placed on the importance of hypertension-related degeneration of the medial layer of the aortic wall, which leads to dilatation of the thoracic aorta, reduced aortic wall compliance, and increased pulse pressures. However, there are no published data that demonstrate unequivocally the existence of a pathogenetic correlation between arterial hypertension and aortic root dilatation. Furthermore, there is no evidence that antihypertensive therapy is effective in the management of nonsyndromic forms of aortic root dilatation. An interesting branch of research focuses on the importance of genetic predisposition in the pathogenesis of thoracic aortic aneurysms. Different genetic backgrounds could explain differences in the behaviour of aortic walls exposed to the same hemodynamic stress. Further study is needed to evaluate these focal physiopathological aspects.

National trends and regional variation of open and endovascular repair of thoracic and thoracoabdominal aortic aneurysms in contemporary practice

Objectives: Successful surgical management of thoracic aortic aneurysms (TAA) and thoracoabdominal aortic aneurysms (TAAA) has historically relied upon open surgical repair (OSR). More recently, the advent and application of thoracic endovascular stent graft aneurysm repair (TEVAR) permutations have become increasingly performed in contemporary practice. To better determine the effect of TEVAR techniques on OSR, we examined national and regional trends in treatment use. Methods: All Medicare patients from 1998 through 2007 undergoing isolated TAA and TAAA repair were analyzed using a clinically validated algorithm using diagnostic International Classification of Disease 9th revision (ICD-9; 441.1, 441.2, 441.6, 441.7, 441.9) codes and procedural (ICD-9 OSR: 38.35, 38.45 and TEVAR: 39.73, 39.79) codes. Differential rates of OSR and TEVAR were compared across census tract regions during the study interval. Results: Total complex aortic repairs increased by 60%, from 10.8 to 17.8/100,000, between 1998 and 2007 (P < .001). A dramatic increase occurred in TEVAR (not performed in 1998, 5.8/100,000 in 2007) during the study period, but OSR rates remained stable during the same interval (10.7 to 12.0/100,000 in 2007, P = NS). There was substantial regional variation for both OSR and TEVAR. This regional variation was greater in OSR (range, 8.8-16.7/100,000) than in TEVAR (range, 4.5-6.9/100,000). Conclusions: Degenerative TAA and TAAA aneurysms are being repaired in the United States at an increasing rate. This reflects the rapid acceptance of TEVAR, which apparently supplements rather than supplants OSR. There appears to be greater regional variation in OSR compared with TEVAR. These data may have significant implications for those interested in the effect of new technologies on health care and cost containment.

Transesophageal echocardiography imaging of subclavian to carotid artery transposition

Paraplegia following endovascular management of thoracic aortic aneurysms is variably reported to occur in 2.7% (range 0-12%) of cases and is believed to be secondary to reduction of anterior spinal artery flow and spinal cord ischemia. This complication occurs more frequently when the left subclavian artery (LSA) is covered, compromising anterior cord blood flow from the left vertebral artery. Prophylactic revascularization utilizing left common carotid artery (LCA) to LSA bypass/transposition has been reported to reduce the incidence of paraplegia, particularly during long segment stenting of the thoracic aorta. A method for visualizing aortic arch branches with transesophageal echocardiography (TEE) has been described in which the LCA and the LSA were successfully identified in 98% and 100% of cases, respectively. Using a similar approach, we report a case in which flow through the LSA-LCA transposition is documented using TEE. A 69-yr-old male presented with pseudo-aneurysmal degeneration of a type B dissection and required endovascular repair of his thoracic aorta. As the planned endovascular procedure would cover the origin to the LSA, the LSA was transposed and then anastomosed to the LCA. Two days following surgery, the patient developed back pain suggestive of impending rupture of his pseudo-aneurysm and underwent urgent stenting of his thoracic aorta. With TEE guidance, verification of the functioning transposition could be assured both before and following stent deployment (video; available as electronic supplementary material). The preservation of collateral circulation to the spinal cord is essential if paraplegia is to be avoided in patients undergoing extensive stenting of the thoracic aorta. In cases requiring long thoracic endovascular repair where the origin of the LSA is covered, the presence of a functioning arterial bypass (Figure 1) helps preserve flow through the left vertebral artery and anterior spinal arterial network and reduces the incidence of paraplegia. In suitable patients, TEE can be used to confirm the presence of a functioning arterial conduit from the carotid artery to the subclavian artery.

Rationale and design of the National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC)

Although the management of thoracic aortic aneurysms (TAAs) has improved significantly, patients presenting with aortic dissections, rupture, or other acute complications of TAAs continue to have high rates of morbidity and mortality. Accumulating data have indicated that many TAAs are due to underlying gene mutations. A comprehensive approach to the study of TAAs resulting from genetic mutations is needed to translate this information into advances in treatment. The National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC) was established to provide a biospecimen inventory and bioinformatics infrastructure to enable research to advance the clinical management of genetically triggered TAAs and related complications. GenTAC is a longitudinal observational cohort study enrolling patients with conditions related to genetically induced TAAs from 5 regional clinical centers in the United States. More than 700 subjects with associated clinical histories, physical examinations, imaging data, and biospecimens have been enrolled in the Registry to date. Enrollment is expected to continue until September 2010. Total enrollment of nearly 3,000 subjects is expected. No interim analysis has yet been undertaken. GenTAC has been established to facilitate studies by GenTAC investigators and others that will advance multiple scientific frontiers in thoracic aortic disease. Genotypic, proteomic, clinical, and imaging data will be integrated systematically with outcomes data to determine the optimal clinical management of patients with genetically induced TAAs.

Etiology, pathogenesis and management of thoracic aortic aneurysm

Given the growing proportion of elderly people in Western societies and the increasing prevalence of chronic hypertension, the management of aneurysmal aortic disease is an ever growing challenge. Although degenerative changes in the aortic wall are common to thoracic aortic aneurysm (TAA) and to various types of dissection in general, TAA can result from specific heritable disorders of connective tissues. Today, increased awareness of vascular diseases and access to tomographic imaging equipment facilitate the diagnosis of TAA, even when asymptomatic. While most TAA cases with ascending aortic involvement are treated with surgical repair (primarily valve-preserving techniques), aneurysms of the distal arch and descending thoracic aorta are amenable to alternatives to classic open repair such as the emerging endovascular treatment techniques. In this Review, we provide a comprehensive overview of the etiology, pathophysiology and clinical management of patients with TAA, and discuss the most recent literature on the condition.

Endovascular management of a descending thoracic mycotic aneurysm: mid-term follow-up

Open surgical repair of mycotic aneurysm is associated with a high surgical morbidity and mortality. Endovascualr graft management of thoracic aortic aneurysm has been associated with a less surgical risk. The role of endovascular graft repair of mycotic aneurysm remains controversial since graft material remains in contact with possible infected tissue. We report the marked thrombosis and marked regression of a thoracic mycotic aneurysm with an endovascular graft at mid-term follow-up.

Endovascular repair in management of thoracic aortic aneurysms

Aneurysms of the thoracic aorta are still potentially life-threatening situations. The conventional operation is still associated with morbidity. Endovascular stent graft repair offers an alternative to conventional operation for management of aortic diseases. Our aim was to report our experience with endovascular stent graft repair of thoracic aortic aneurysms. Between November 2002 and October 2005, endovascular stent graft repair was performed in 26 patients: post-traumatic aortic aneurysm (n=4), Type B dissection (n=3) and descending thoracic aortic aneurysm (n=19). The deployed stent graft systems were Talent-Medtronic (n=14) and Excluder-Gore (n=12). Successful deployment of the stent grafts in the appropriate position was achieved in all patients. There was neither hospital mortality nor paraplegia. Late and non-procedure related death occurred in only one patient (3.8%). An average of 40% shrinkage of the aneurysmal space was observed. There was no early mortality and endoleaks. The median intensive care unit and hospital stay times were 1 and 7 days (range 4-13 days), respectively. Post-operative computed tomography scans were obtained in all patients and complete thrombosis was observed in the false lumen of dissecan aneurysms (n=3) and sac of saccular aneurysms in 25 patients. Mean follow up time was 17.1+/-5.4 months. Endovascular stent graft treatment for treatment of thoracic aorta aneurysm, Type B dissection and traumatic disease of the thoracic aorta is technically feasible. Although the short and mid-term results are encouraging the long term results will determine the future of this treatment.

Endovascular management of thoracic aortic aneurysms. Preoperative imaging and device sizing

Thoracic aortic pathology in a variety of forms continues to represent a significant health challenge. The incidence of thoracic aortic aneurysms (TAAs) is estimated to be as high as 10 cases per 100,000 population per year, acute aortic dissection occurs in 10 to 20 individuals per million population, and traumatic aortic tears occur in up to 18% of motor vehicle accidents. Until recently, the only effective treatment method was surgical graft replacement, involving high morbidity and, at times, technically complex operations. Endovascular stent-graft repair recently emerged as viable alternative and has now gained acceptance as an innovative, safe treatment method associated with substantially less morbidity and reduced hospital stay. Unlike open TAA repair, where the surgeon can make decisions on graft size at the time of surgery, endoluminal repair requires meticulous preoperative imaging to precisely define the aneurysm morphology and choose the appropriate size graft. This quickly became evident in the early era of endovascular abdominal aortic aneurysm (AAA) repair, when failure to correctly measure the aneurysm led to endoleaks, graft thrombosis, graft misalignment, and failure to exclude the aneurysm. It is particularly true for aneurysms of the thoracic aorta, where high flow velocities and acute arch angles pose a formidable challenge in accurate graft placement and aneurysm exclusion. Evaluation must include measurements of various diameters and lengths of the aortic arch and proximal and distal thoracic aorta. In addition, iliac artery size, tortuosity, angulation, and calcification may impact delivery and need to be taken into account. This chapter summarizes the most important aspects and highlights common pitfalls in endograft sizing before endovascular repair of TAA.

Acute traumatic rupture of the thoracic aorta: Delayed treatment with endoluminal covered stent. A report of two cases

Acute traumatic rupture of the thoracic aorta: Delayed treatment with endoluminal covered stent. A report of two cases

Cardiopulmonary bypass, hypothermic circulatory arrest and left postero-lateral thoracotomy for the management of thoracic aortic aneurysms

Cardiopulmonary bypass, hypothermic circulatory arrest and left postero-lateral thoracotomy for the management of thoracic aortic aneurysms

Successful Surgical Management of Thoracic Aortic Aneurysm in a Right-Sided Aortic Arch

A 24-year-old woman with a multilocular sacciform aneurysm in a right-sided aortic arch was successfully treated by aneurysmorrhaphy. Although the cause of the aneurysm could be attributed to congenital factors, its growth was considered to be related to the features of the right-sided aortic arch; strong haemodynamic forces were caused by sharp curving of the aorta which started from an unusually high position and subsequently had a decreased radius.